Antenna



Nov. 14, 1933- H. o. PETERSON Filed March 29, 1929 ATTORNEY c ste s; 1

Patented Nov. 14, 1933 W P- STATES PAT T O FIC V ANTENNA I Harold 0.Peterson,- Riverhead, N. Y.,assignor to Radio Corporation of of DelawareAmerica, "a corporation Application March 29, 1929, Serial No; 350,884,Renewed January z l, 1933 I Y zoclaims. (011250 33;

, This invention relates to antennas, and more particularly todirectional antennas for use with energy of very short wave length? v Inmy copending application Serial Number 5 2313M, filed November 8, 1927,which has issued as U. S. Patent No. 1,821,402, granted September 1,1931, I have disclosed a directional antenna comprising a pair ofrelatively closely spaced feeder members extending in the directionv ofdesired communication, with a plurality of antenna conductors extendingtransversely and externally of the feeder members, and loosely coupled.thereto through; relatively high impedances. The primary object of mypresent invention is to improve the directional properties of such anantenna. To this end I now have devised an antenna which, like thatalready referred to,- 7 includes a pair of relatively closely spacedfeeder members extending in the direction of desired communication, anda plurality of antennas coupled thereto, but in accordance withthepresent invention, each of these antennas comprisesa pair of conductorswhich divergein thedirection of desired communication.

1 Such a pair of diverging conductors constitutes an antenna which isitself somewhat directive in the direction of divergence of theconductors, the operationbeing in this respect considerably superior tothat of 'a simple doublet. i In conse- ;quence,' the directionalproperty of the complete antenna system is also increased, beingapproximately equal to the product of the directivity of the system whennondirectional antennas are used, and the directivity of the individualantennas comprising the system. Y 7 In order that the antennas may allaid one another they should operate ata phase. displacement equal'to thephase displacement of the signalling Wave in space over a distanceequal, to the distance between the points of coupling of the antennas tothe feeder members. Furthermore, energy should be transferred along thediverging conductors at such a velocity'that'the equivalent 'velocityinthe direction of communication, that ,is, the cosine component, isequal. to the velocity of the signalling wave in space. I If ,the angleof divergence of the conductors is very; small then .the cosine isnearly unity, and it may be assumed that the usual. velocity along theconductors will be sufficiently great. However, if the angle ofdivergence-isvery; great, the velocity along the conductors mustbeconsiderably increased, and to provide for the necessary increase invelocity I insert series condensers in the antenna conbe madeto flowalong the feeder membersat or Assuming that the antennasare made tooperate at the proper. phase difference, and that the proper velocityis-obtained along the antenna conductors, it isstill necessary that theenergy near the velocity of the wavein space. The ve-'- O locity whichnormally would exist on a pair of feeder members is satisfactory,assuming no load.- ing, but upon loading the feeder members with theantennas, this velocity is aptto be greatly reduced.- To avoid thiseffect I couple the an tennas to the feeder members through highimpedances which make the coupling sufl'iciently loose so that thevelocity of energytransfer' on the feedermembers isnot materiallyreduced.

In order to make the antenna unidirectional it is desirable to preventreflection of energy on either the antenna conductors or the feedermembers, In the case of a receiving antenna, energy approaching from therear, if refkcte'd, acts like energy approaching from .the' front of theantenna. In order to prevent the possibility of. reflection Iemploysurge impedances at the remote end ofthe feeder members, and preferablyalso at the open ends of the diverging antenna conductors.

My invention is further described in the following specification, whichis accompanied by'a drawing in which Figure 1 indicates oneform of myinvention; Figure 2 is a modification in which the antenna conductorshave a large angle of divergence; while" Figure 3 is a vector diagramexplanatory of Figure 2. .Q

Referring to Figure l it will-be seen thatv the antenna includes a pairof relatively closely spaced feeder members 2, which extend i'n. thedirection ofIdesired communication, and which at the near end areconnected to a receiver 4 through a transmission line 6, and at the far.end are closed by a surge impedance 8.'- To the feeder members at spacedintervals are..-couple d antennas, each comprising a pair ofconductorsl0 trated, 'of small coupling condensers -16. The

object of these impedances is to couple the antennas to the feedermembers loosely, fo r in such case I have found that the loading of theantennas on the feeder members does not very greatly reduce the velocityof energy transfer along the feeder members, so that the phasedisplacement between the energies on the antennas, which is equal to thephase displacement of the wave travelling in space, is kept equal tothat of the energy travelling on the feeder members. Figure 2 is quitesimilar to Figure 1, except that in this case the antenna conductorsdiverge very much more abruptly. up the velocity of energy flow alongthe antenna conductors they are arranged with series condensers 20. Theobject of these condensers may better be explained by reference toFigure 3, in which it will be seen that if the dimension AC is to equalthe velocity of the wave inspace, the velocity AB, along the antennaconductors, must be made greater in proportion to the secant of theangle of divergence of the antenna conductors, for the space Wave,moving parallel to the feeder'members, cuts the antenna conductors at amore rapid rate owing'to the slope of the antenna conductors. Theinsertion of'series condensers serves to increase the velocity of flowof the energies along the conductors, and so to retain the desiredinitial phase displacement until these energies reach the feedermembers.

Surge impedances may be used at the open ends of the antenna conductors,as at 14, but

with the close spacing indicated in Figure 2,

they are not essential.

The plane of polarization of this antenna corresponds to the plane ofthe antenna.

When the antenna is used for transmission considerable loss may takeplace in the surge impedances 8 and 1&1, and these should preferably beeliminated, reflection being prevented by proper attenuation of thetransmission energy along the antennas and feeder members.

I claim:

1. The combination with a single receiver of a directionalantenna systemincluding a pair of relatively closely space-d feeder members connectedto said receiver extending in the direction of desired communication,and a plurality of antennas simultaneously coupled thereto, each of saidantennas comprising a pair of conductors which diverge in the directionof desired communication. v

2. A directional antenna system including a pair of relatively closelyspaced feeder members extending in the direction of desiredcommunication, a plurality of antennasv loosely coupled thereto atspaced intervals through impedances of relatively high magnitude, eachof said antennas comprising a pair of conductors which diverge in thedirection of desired communication.

3. A directional antenna system including a pair of feeder membersextending in the direction of desired communication, and a plurality ofantennas coupled to the feeder members at spaced intervals, each of thesaid antennas comprising a pair of conductors which diverge in thedirection of desired communication, and which are arranged to operate ata phase difference equivalent to their spacing along the feeder members.

4. A directional antenna including a pair of feeder members extending inthe direction of desired communication, and a plurality of antennascoupled thereto at spaced intervals, each of said antennas comprising apair of conductors which diverge in the direction of desired com Inorder to speed.

munication, said conductors being provided with series condenserswhereby the antennas may be made to operate at phase difierencesequivalent plurality of collecting antennas loosely coupled to thefeeder members at spaced intervals through relatively high impedances,each of said antennnas comprising a pair of pick-up wires diverging inthe direction of the desired transmitting station, in order to increasethe directivity of the antenna system.

6. A directional receiving antenna including a pair of relativelyclosely spaced feeder members extending in the direction of desiredreception, a surge impedance connected at the remote ends of the feedermembers, a plurality of collecting antennas loosely coupled to thefeeder members at spaced intervals through relatively high impedances,each ofsaid antennas-comprising a pair of pick-up wires diverging in thedirection of the desired transmitting station, in order toincrease thedirectivity of the antenna system. Y V

7. A directional receiving antenna including a pair of relativelyclosely spaced feeder members extending in the direction of desiredreception, a plurality of collecting antennas loosely coupled to thefeeder members at spaced intervals through relatively high impedances,each of said antennas comprising a pair of pick-up wires diverging inthe direction of the desired transmitting station, and surge impedancesconnected at theremote ends of the feeder members and the antennas, inorder to prevent back end pick-up.

8. In an extensive antenna system for directional communication, aplurality of spaced feeder members extending in the direction of desiredcommunication, a plurality of auxilliary members connected to each ofsaid spaced feeder members and diverging in the direction of desiredcommunication, and means in each of said auxilliary members for insuringthat the energy flowing therein is in phase with the energy in thefeeder members.

9. In an extensive directional antenna system, a plurality of linearmembers extending in the direction of desired communication andconnected at the far end through an impedance, a plurality of auxilliarymembers spaced in pairs along said linear members and coupled thereto,said auxiliary members diverging in' the direction of communication, andmeans in each of said auxilliary members for determining the electricallength thereof such that each member has a phase difference bearing'adefinite relation to its physical spacing along said linear members.

10. In adirectional antenna system a pair ofspaced feeders extending inthedirection of desired communication, a plurality of pairs ofauxilliary members coupled to'said feedenmembers and spaced therealong,each of said auxilliary members being inclined towards the desireddirection of communication, an impedance connecting the terminal of eachauxiliary member to ground, and series capacities ineach of saidauxilliary members. V

11. In a directional antenna system, a pair of spaced feeders extendingin the-direction of desired communicatioma plurality of pairs ofauxiliary members coupled to saidfeeder members and arranged at an anglewith'the desired direction of communication, those terminals of said*auxilliary members which are not coupled to i said feeders beingeffectively coupled togetherby bersconnectedto said high frequencyapparatus and extending in the direction of desired communication, aplurality of pairs of auxiliary members coupled to'said feeder membersand arranged at an angle with the desired direction of communication,series reactances in each-of, said auxiliary members, and a surgeimpedance across that end of said feeder members located away from saidhigh frequency apparatus.

14. A directional antenna system comprising a two wire transmissionline, a pair, of linear antenna elements diverging in the desireddirection of communication, the more closely spaced ends of saiddiverging elements being coupled to said transmission line, and acircuit including a resistance effectively coupling together the ends ofsaid linear elements which are spaced farther apart.

15. A directional antenna system comprising a two wire transmissionline, a pair of antenna elements diverging in the desired direction ofcomrnunication, the more closely spaced ends of said diverging elementsbeing coupled to said transmission line, a circuit including aresistance effectively coupling together the ends of said antennaelements which are spaced farther apart, and series reactances in eachof said antenna elements.

16. In a directional antenna system, high frequency apparatus, a twoWire transmission line connected to said high frequency apparatus, apair of linear antenna elements diverging in the desired direction ofcommunication, the more closely spaced ends of said diverging elementsbeing coupled to said transmission line, and an impedance connectedacross that end of said transmission line which is located away fromsaid high frequency apparatus.

quency apparatus, a two wire transmission line connected to said highfrequency apparatus, a

.pair of antenna elements diverging inthe desired direction ofcommunication and coupled to said 17. In a directional antenna system,high fre-' transmission line, lumped reactances serially con- I nectedin each of said elements, and asurge impedance connected across that endof said transmission line which. is located away from said highfrequency apparatus.

18. In a directional antenna system, high frequency apparatus, a twowire transmission line connected to said high frequency apparatus, a

pair of linear antenna elements diverging in the desired direction ofcommunication, the more closely spaced ends of said diverging elementsbeing coupled to said transmission line, a circuit including aresistance effectively connecting together the ends of said linearelements which are spaced farther apart, and an impedance connectedacross that end of said two wire transmission line which is located awayfrom said high frequency apparatus.

19. In a directional antenna system, high frequency apparatus, and a twowire transmission line connected to said high frequency apparatus, apair of antenna elements diverging in the desired direction ofcommunication, the more closely spaced ends of said diverging elementsbeing coupled to said transmission line, lumped reactances seriallyconnected in each of said elements, a circuit including a resistanceeffectively connecting together the ends of said linear elem nts whichare spaced farther apart, and a surge impedance'connected across thatend of said two wire transmission line which is located away from saidhigh frequency apparatus.

20. In a directional antenna system, high frequency apparatus and a twowire transmission line connected to said high frequency apparatus andextending in the direction of desired communication, a pair of linearantenna elements coupled to said two wire line and arranged at an anglewith the desired direction of communi-' cation, the more closely spacedends of said antenna elements being coupled to said transmission line,and a surge impedance coupling together the ends of the wires of saidtransmission line furthest away from said high frequency apparatus.

HAROLD O. PETERSON.

